There are known commercial aircrafts (CBA vector 123, SARA, AVANTI, 7J7) powered with propeller engines located in the rear part of the aircraft supported by the fuselage by means of pylons.
One of the problems raised by this aircraft configuration is related to failure events such as a PBR (“Propeller Blade Release”) i.e. an event where a blade of one of the propeller engines comes off and hits the fuselage, a UERF (“Uncontained Engine Rotor Failure”), i.e. an event where a part of the rotor of the engine brakes, it is released and hits the fuselage, an ice shedding event where ice shedding created in the tips of the blades can be thrown at high speed over the fuselage, or any other “Large Damage” event.
The design of the aircraft parts subjected to said events shall therefore take into account all possible damage scenarios and guarantee safety by assuring structural integrity and the capability of maintaining sufficient stability and proceed to an aircraft safe landing.
Said events are particularly important for fuselages made of composite materials that is a current trend in the aircraft industry. Those materials can be less tolerant to the damages caused by said events than other materials, in particular, metallic materials.
The composite materials that are most used in the aeronautical industry consist of fibers or fiber bundles embedded in a matrix of thermosetting or thermoplastic resin, in the form of a preimpregnated or “prepreg” material. Its main advantages refer to:                Their high specific strength with respect to metallic materials. It is the strength/weight equation.        Their excellent behavior before fatigue loads.        The possibilities of structural optimization hidden in the anisotropy of the material and the possibility of combining fibers with different orientations, allowing the design of the elements with different mechanical properties adjusted to the different needs in terms of applied loads.        
Although the aircraft industry demand constantly methods for optimizing the structural design of aircraft parts there are not known methods for optimizing the structural design of aircraft parts subjected to multiple damages caused by a PBR event, an UERF event, an ice shedding event or any other similar event.
The present invention is oriented to the attention of said demand.